NAR300 system for high temperature
Installation
Hauser
27
5.2.1
Installation/mounting-related precautions
1. Installation of debris protection, a roof or a cover is recommended to prevent debris
or snow from entering the pit. If there is snow accumulation on the float sensor, each
50 g of snow accumulation will cause an increase in draft by 1 mm (0.04 in),
resulting in reduced sensitivity. If there is a risk of ambient temperature exceeding
50 °C (122 °F), install a sun shade to protect the float sensor from direct sunlight.
Mount a covering above the top of the pit inlet to avoid submerging the float sensor
housing if the pit water overflows due to heavy rainfall, etc. If the float sensor
becomes submerged, a malfunction or damage may result.
2. If the float sensor becomes off balance (tilted by approximately 3 ° or more), it may
cause a malfunction or delayed alarm. To prevent this, use a float guide as much as
possible and arrange the cables and chains strategically.
3. Install a screen at the pit inlet so that debris can be removed. Periodically inspect and
clean the sensor and the pit as clogging caused by debris and foreign matter may
result in a malfunction.
4. Attaching a chain to the side ring on the float sensor head ahead of time will improve
convenience. However, each 50 g of increased load on the float will increase the draft
by 1 mm (0.04 in), resulting in reduced sensitivity. Also, if a chain is used to prevent
the float sensor from flowing out, do not yank on the chain during inspection, etc.
5. When the pit is completely filled with water, an oil layer will not be formed inside the
pit even if oil spills out. Ensure that the water is drained as necessary so that an oil
layer can be formed.
6. Do not yank on the cables or carry the device by holding on to the cables as this may
cause a malfunction and/or poor waterproofing.
7. If the valve is constantly open, ensure that an oil layer can be formed such as by
bending the tip of the discharge nozzle downwards by at least 100 mm (3.94 in).
Failure to do so may cause oil to discharge from the pit before it can form a
detectable layer on the water surface, resulting in a delayed alarm or detection
failure. For pits without a discharge nozzle as shown above, install an oil-water
divider so that an oil layer can be formed.
8. Install a divider to prevent large waves, cross-currents or water from splashing onto
the float when liquid flows in.
9. If the pit is too large, divide the pit with an oil separator. Oil leakage cannot be
detected unless there is significant outflow of oil in proportion to the surface area.
10. Install NAR300, NRR261 and a sensor I/F Ex box at least 50 cm (1.64 ft) apart from
each other.
